Submarine-launched ballistic missile tested-THE HINDU- 20-01-2020

Context:

India successfully test-fired the 3,500-km range submarine-launched ballistic missile, K-4. The test was carried out by the DRDO from a submerged pontoon off the Visakhapatnam coast around noon.

Significance:

Technological breakthrough:

The missile ejecting from a submerged platform to the surface [sea] possess several technical challenges. There are very few countries which have managed to achieve this.
This technological breakthrough marks an important step towards achieving indigenization of defence technology.

Edge over other missiles of the same class:

The Circular Error Probability (CEP) of the K-4 is much more sophisticated than most countries which possess similar missiles. The CEP determines the accuracy of a missile. The lower the CEP, the more accurate the missile would be in targeting.

Increased range:

INS Arihant, the first and only operational SSBN, is armed with K-15 Sagarika missiles with a range of 750 km. The K-4 has an enhanced range.
The K-4 missiles will be the mainstay of the Arihant class of indigenous ballistic missile nuclear submarines and will give India the stand-off capability to launch nuclear weapons submerged in Indian waters.
Standoff weapons are missiles or bombs which may be launched at a distance sufficient to allow attacking personnel to evade defensive fire from the target area. Typically, they are used against land- and sea-based targets in an offensive operation.

Second strike capability:

The nuclear triadis a three-pronged military force structure that consists of land-launched nuclear missiles, nuclear-missile-armed submarines and strategic aircraft with nuclear bombs and missiles.
India completed its nuclear triad with the commissioning of INS Arihant in August 2016, which was India’s first submarine built indigenously.

The K-4 being nuclear-capable, it will also enhance the second strike capability of India.
In nuclear strategy, a second-strike capability is a country’s assured ability to respond to a nuclear attack with powerful nuclear retaliation against the attacker.

Additional Information:

SSBN is the US Navy hull classification symbol for a nuclear-powered, ballistic missile-carrying submarine. The SS denotes “submarine” or “submersible”, the B denotes “ballistic missile,” and the N denotes “nuclear powered.”

About INS Arihant

The Advanced Technology Project (ATV) began in the 1980s and the first of them, Arihant, was launched in 2009.
INS Arihant, the first and only operational SSBN is armed with K-15 Sagarika missiles with a range of 750 km.
Given India’s position of ‘No-First-Use’ (NFU) in launching nuclear weapons, the SSBN is the most dependable platform for a second-strike.
Because they are powered by nuclear reactors, these submarines can stay underwater indefinitely without the adversary detecting it.
The other two platforms — land based and air launched are far easier to detect.